Apparatus for spraying adhesive on cartons



Oct. 13, 1964 E. E. MARSHALL ETAL 3,152,923

APPARATUS FOR SPRAYING ADHESIVE 0N CARTONS Filed No r. 7, 1961 v 4 Sheets-Sheet l [NI/M70178 EDWARD E. MARSHALL JOHN E. ULLMAN ATTORNEX' Oct. 13, 1964 E. E. MARSHALL ETAL 3,152,923

APPARATUS FOR SPRAYING ADHESIVE ON CARTONS Filed NOV. 7, 1961 4 Sheets-Sheet 2 as i. Q 93 67 95 2 FIG. 2 66 INVENWRS EDWARD E. MARSHALL JOHN E. ULLMAN ATTORNEY O 13, 96 E. E. MARSHALL ETAL 3,152,923

APPARATUS FOR SPRAYING ADHESIVE 0N CARTONS Filed NOV. '7, 1961 4 Sheets-Sheet 3 1 "o 108 1 -91 y! IVA /6T FIG. 4 Y4 INVENTORS ED E. MARSHALL J0 ULLMAN ATTORNEY Oct. 13, 1964 E. E. MARSHALL ETAL 3,152,923

APPARATUS FOR SPRAYING ADHESIVE on CARTONS 4 Sheets-Sheet 4 Filed Nov. 7, 1961 mvmrons EDWARD E. MARSHALL JOHN E. ULLMAN M4 4 5M4 FIG. 6

ATTORNE Y I 3,152,923 I APPARA'EEE SERAYKNG ADHESIVE GNCARTGNS Edward E. Mai-snail, Meadowbroolr, and John Ulhnan, Drexelli-iiiLPa, assignors to Huntingdon industries Incorporated, Bethayres, Pen, a corporation of Pennsylvania lFiled Nov. "'7, 1951, Ser. No. 15%,31'7 QCiaims. (Cl. llS--2) corrugated paper carton whichcontains, for example,

twelve or twenty-four cans.

Heretofore, it has been suggested to utilize a single adhesive spray gun to spray adhesive on the flap of a carton. However, in order to cover a suflicien't area of the flap to insure sealing, the'spray gun had to be placed a considerable distance from the flap. Thispresented considerable difficulty in that the spray area was diilicult to control, and a considerable amount of adhesive was lost throughoverspraying. Moreover, the-overspray settled on adjacent parts of the machine and there congealed, and thereby created a messy maintenance problem.

It is an object of the present invention to overcome the aforementioned problems, and to provide a spray gun apparatus which sprays adhesive on the flap of a carton in a sharp, easily controlled pattern.

It is another object to provide a spray gun apparatus which may be substituted as a unit for the conventional ther become apparent hereinafter and in the drawings, in

which: y l a FIG. 1 is anoverall assembly view of thespray apparatus constructed in accordance with this invention;

FIG. 2 is a view in front elevation of a spray gun constructed in accordance with this invention;

FIG. 3 is a view in top plan of the spray gun shown in FIG. 2;

FIG. 4 is a view invertical section of the spray gun shown in FIG. 2; FIG. 5 is a view in section on an enlarged scale of the spray head of the present invention; and

FIG. 6 is a schematic diagram of the electrical circuit of the invention. i Although specific terms are used in the following description for clarity, these terms are intended to refer tion selected forillustration in the drawings, there is shown a compressed air source ll, an air filter 12 connected to compressed air source 11 by conduit 13, a main air line l -l extending from air filter l2 and having branching therefrom a spray gun control line 15, atomizingair lines 16 and i7, and a glue pot line 18.

, United States Patent 0 "ice a aisaszs Patented Oct. 13,1964

Spray gun control line l5-includes an air-regulator 21 for controlling the pressure of the an operating the spray guns, a lubricator 22 which puts oil into the air to lubricate the spray gun parts, gun control valves 23, 24 which actuate the spray guns, conduit 25 which connectsgun control valve 23 with one side of the piston of spray v gun 2 6, and conduit 27 which connects gun control valve 23 withthe other side ofthe piston of spray gun 26. Similarly, conduits 31 and 3:2, connect gun control valve 23 with each side of the piston of spray gun 33.

In like manner, gun control valve 24 is connected to each side ofothe piston in spray gun 34-by conduits 35 and regulates the pressure of the 'atomizing air in spray guns I 37, 34, atomizing air valve 47 (which, like valve 43, is a pilot operated 2-way valve that turns the 'atornizing air on and off in the spray guns), and conduits 48, 49 which connect atomizing air valve 47 to spray guns'34 and 37, respectively.

It is to 'be noted that atomizing air valve, 43 connects to the upper two spray guns 26 and 33, while atomizing air valve 47 connects to the lower positioned spray guns 37 and 34. The apparatus is arranged in this manner because it has been found invpractice that thelo'wer guns $7, 34 (which shoot upwardly) require more atomiz'ing air pressure than the upper guns 26, 33 (which shoot downwardly). Gun control valve 2 3 controls the operation of the upper spray guns 26 and 33, while gun control valve 24 controls the operation of the lower spray guns 37 and 34. Accordingly, it maybe seen that valves 23 and 43 operate as a team 'to control the upper guns 26 and 33, while'va'lves 24and 47-operate asateamfto control the lower spray guns 37 and34. j I

Glue pot line lfiincludes an air regulator. 52 andconnects mainline "14 with pressurized glue pot 53. Conduits 54-57 connect gluepot 53 to the spray guns.

FIGS. 4 and 5 show a spray gunwhieh include's a housing #61 adapted to be mounted in close proximity to a flapof a carton and having a cylinder 62 formed tlier'ein, a piston 63 having a'piston head 64 positioned in cylinder 62 and apiston rodf65 extending upwardly therefrom, a needle bar '66 mounted on the top ofpiston rod 65 arid adapted to be reciprocated thereby, a spray head 67 mounted on housing 61 above needle bar 66 and having a plurality of adhesivespray orifices ofi, and a longitudinally movable needle 71 extending from each adhesive orifice- "68 .and operatively connected to needle bar 66.

Piston head '64 is double acting and is provided with sides .72, 73. Compressed air from gun control valve24, for example, may. be connected to exert pressure on side 73 of pistonhead'od in gun 37'by connecting the conduit 33 to a port 74 formed in cylinder body cap 75 which'is mounted on the bottom of cylinder housing '61. Compressed air from gun control valve 24 may be connected to side '72 of piston head 64 by connecting theconduit 39 to port 76which isformed in housing 61.

An"'O-ri'ng "77 provides a seal between housing '61 and cylinder body cap '75, and O-ring '78 is mounted in a groove 81 in piston head"'64to provideaseal between side 72 and side 73 of piston head 64.

Piston rod 65 is centered in a guide liner 82 mounted in an opening 83 in housing 61, and an Q-ring S t-provides against side 73 of piston head 6 moves the piston head '64 in the direction toward adhesive discharge orifices 68 .and thereby moves needle bar 66 and needles 71 toward adhesive discharge orifices 68 to move the tips of needles 71 into orifices 68 to stop the discharge of adhesive therefrom. v

The top of piston rod is received in an opening in a lower horizontal member 86 of needle bar 66, and is held tightly therein by asocket pipe plug 87.

Needles 71 are provided with a tip 88, a shaft 91, and a head 92. Head 92 is received in a space in needle bar 66 between lower horizontal member 86 and upper horizontal member 93 which is provided with slots 94 that receive shafts 1 but do not pass needle heads 92.

Each needle head 92 is supported by a spring assembly 95 which presses upwardly to insure that tip 88; of needle 71 is seated properly in orifice 68 of adhesivedischarge nozzle 96, despite any manufacturing variations of. the

dimensions of tips' 88 or the adhesive discharge orifices 68.

Spray head 67 includes a base 97 which is bolted to a cap 98. A nozzle 101 is seated in an opening in cap 98 and forms an annular air discharge orifice 102 around the tip of adhesive discharge orifice 68. Atomizing air may be connected into annular air discharge orifice1tl2 from atomizing air valve47 through conduit 49 into an air passage 1193 formed in base 97. Air passages 104 in cap 98 connect air passage 103 to the annular air discharge orifice 102.

'An adhesive chamber 105 is formed in base 97 andis 41 ated limit switch 137 is connected in conductor 132 and is actuated to pulse the guns to spray the glue.-

A test circuit is provided which permits testing the operation of the apparatus. The test circuit includes a conductor 138 and a contact 141 which by-passes auxiliary contact and contact 115, and connects tocontacts 125, 126 of solenoids 128, 129. The test circuit also includes a conductor 142, and a contact 143 which by-passes limit switch 137 and connects to contacts 133 and 134 and solenoids 135, 136. l

In automatic operation, contact 116 is closed and contacts 141 and 143 are open. If no carton is positioned beneath the guns to close the limit switch 124, the circuit is open to solenoids 128, 129 of the atomizing air control valves 43, 47, and the circuit is also open to the solenoids 135, 136 of the gun control valves 23, 24. Accordingly, the spray guns are not "actuated. v v

In manual-test operation, contact 116 is open and contacts 141 and 143 are closed to thereby by-pass the limit switch 124-, and by-pass the limit switch 137.

In automatic operation, the flap of a carton is passed in close proximity to the tip of a spray gun, such as spray gun 3'7, atomizing air valve 47 is actuated by carton operated limit switch 124.

Then, piston head 6413 moved away from adhesive discharge orifices as by the operation of gun control valve 24 (actuated by cam operated limit switch 137) sending compressed air through conduit 39 to impinge against side '72 of piston head 64. Piston 63 moves needle bar 66 andneedles 71 away from orifices 63 to withdraw needle tips fifitherefrom, and the previously actuated atomizing airfrom annular orifices 102 impinges against the ad hesive being discharged from orifices 68 and carries the adhesive to the surface or the carton'fiap. Then gun control valve 24 is actuated by cam operated limit switch 137 to send compressed air through conduit 39 to impinge against the side 73 of piston head 64 to move piston connected to the interior of adhesive discharge nozzle 96 and to adhesive discharge orifice 68. Adhesive may be connected into adhesive chamber 195 from glue pot 53 by means of conduit 57 (see FIG. 1).

To prevent adhesive from seeping out along the shaft 91 of needle 71, packing1tl6 is positioned aroundshaft 91 and is held in place by a packing nut v1157.

It is to be noted that spray head 67- and needles '71 may be removed from housing 61 and replaced as a unit by un-.

screwing bolts 1% and sliding the needles '71 out of the slots 9 in the upper horizontal member, 93 of needle bar 66. This easy removal as a unit for inspection, cleaning, and repair is one of the outstanding advantages of the invention. i

FIG. 6 shows a schematic wiring diagram of the invention which includes line conductors 111, 112, fused disconnect switch 113, an operating circuit which includes a conductor 114 having connected therein an auxiliary contact 115 on the drive motor starter which opens the circuit to the spray guns if the motor stops, a contact 116 guns, or all guns together. Contact 125 is connected to a solenoid 128 which controls the actuation of atomizing air valve 43 of the upper guns 26, 33, and contact is connected to a solenoid 129 which controls the actuation of atomizing air valve 47 of the lower guns 37, 34.

A conductor 132 is connected between conductor 114 and switch contacts 133, 134. Contact 133 is connected J to a solenoid 135 which controls the'operation of gun control valve 23 of'the upper guns, and contact 13 1 is connected to a solenoid 136 which controls the operation of gun control valve 24 of the lower guns. A cam operof a selector switch 117 which is operated by a lever118 63, needle bar 66, and needles 71 toward orifices 68- to close orifices 68 by inserting the tips 88 of needles 71 therein. Then atomizing air valve 47 shuts off the atom- .izing air gqing through gun 37. A time delay mechanism in valve 47 delays the shutting off of the atomizing air until after'adhesive discharge orifices 6% have been closed by needles 71.

The method for spraying adhesive on the flaps of a carton of the present invention includes the steps of passing-the flaps of a carton inclose proximity to the tip of a spray gun, passing atomizing airfrom a plurality it and carry it to the surtace of the carton fiaps, stopping the passage of adhesive from the adhesive orifices, and

maintaining the passageofatomizing air from the atomizing orifices for a predetermined time period, to clean the tip of the spray head and prevent adhesive from congealing thereon. Then the passage of atomizingair from the atomizing orifices is stopped. The carton flap is moved relative to the tip of the spray gun during the spraying operation so that the flap receives stripes of adhesives. Such stripes may overlap to form a band.

The present invention'provides a number of advantages over the prior art. it uses a lesser quantity of adhesives, it reduces the time required to compress and seal the glued flap,- and it requires less maintenance than roll type adhesive' applicators. Instead of applying a gummy layer, which is thicker than needed for efiective sealing, the present invention sprays on a controlled mist of tiny droplets which saves material, dries faster, and reduces compression time. Messy maintenance problems that go with rollers and glue pots are eliminated.

The specially designed spray heads with their multiple orifices deposit the adhesive on the carton flap and prevent overspray.

may be positioned to spray abroad band of adhesive for inaximumfflap coverage, or it may he positioned-so as to spray thin stripes of controlled width on the fiap when less coverage is desired.

Another important advantage is provided by the v selector switch 127 which enables the operator. to select to spray top 'flaps, or to spray -bottomflaps, or to spray all flaps, merely by the flick of a switch.

The present invention is easily adapted to new or existing machines. It;is not necessary to remove the roller type applicators when installing the spray kit of the present invention unconventional ease sealers. The spray kit of the present invention functions with either resin or dextrin adhesives.

Although spraygunapparatus including four spray guns have herein been illustrated and described, it will be;

realized that spray gun apparatus-including only two guns for spraying either thetop flaps or the bottom flaps of a case may beprovided. The two gun spray apparatus may i be especially desirable for either re-shippers who receive cartons having one set of flaps alreadysealed, since such manufacturers glue only either the bottom flaps or the It :isto be understood that the form of the invention herewith shown and described is to be taken as a'presently preferred embodiment. Various changes may be made in the shape, size andarrangement of parts. For example, equivalent elements may be substituted for those illustrated and described herein, parts may be reversed, and certain features of the invention may be utilized in dependently of the use of other features, all without departing from the spirit or scope of the invention as defined in the subjoined claims.

The claimed invention:

1. Spray gun apparatusfor spraying adhesive on the flaps of a carton comprising a spray gun having a spray head with a plurality of adhesive-spray orifices and atomizing-air orifices, an air filter adapted to be connected to a source of compressed air, a spray gun control line connected to said air filter and connecting together an air pressure regulator, an air lubricator, a gun control valve, and actuating piston of said spray gun, an atomizing air line connected to said air filter and connecting together an air pressure regulator, an atomizing air valve, and the atomizing air orifices or" said spray gun, said atomizing air valvebeing separate from said spray gun and adapted to be located at a point remote from the spray gun, a glue line operatively connected to said air filter and connecting .together an air pressure regulator and pressurized glue means, and a glue conduit connecting said glue means tothe adhesive-spray orifices of said spray gun, said spray gun having a longitudinally movable needle extending from each of said adhesive-sprayorifices, and means for operating said needles in unison to open and close said adhesive-spray orifices.

2. The spray gun apparatus defined in claim 1, wherein is provided cam operated limit switch means connected to said gun control valve for actuating said control valve to operate the spray guns.

3. The spray gun apparatus defined in claim 1, wherein is provided carton sensing switch means connected to and connecting together an air pressure regulator, an air lubricator, upper and lower gun control valves, and ac- I formed therein, a piston having a piston head positioned tuating pistons of'the upper and lower pairs of spray guns; an atomizing air line connected to said air filter and conn'ecting-together an air regulator, upper andlower' atomizing air valves, and the atomizing air orifices of said sprayguns; said atomizing air valve being separate from said-spraygun and adapted to be located at'a point remote from the spray gun; a glue line operatively connecting togetherfsaid air filter and an air pressure regulator and pressurized glue means; a glue conduit connecting said glue means 'tothe adhesive-spray orifices of said spray guns; and 'selector switch means connected to said gun and atomizing air valves for selecting the spraying of top fiaps, or sprayingof*bottonrflaps, or spraying-of all flaps; each of saidspray guns having a, longitudinally movable, needle extending from each of said adhesivespray orifices, and means for operating said needles in unison to open and close said adhesive-sprayorifices.

5. A spray'gun for spraying adhesive on the flaps of the carton comprising a housing adapted to be mounted in clos'eproximity to 'a flap of a carton and having acylinder "formed therein, a piston having a piston headpositione'd in-said cylinder and a'piston rod extending therefrom, a needle bar connected to said piston rod and reciprocable thereby, a'spray head detachably mounted on said housing and having a plurality of adhesivespr'ay orifices contained therein, and a longitudinally movable needle extending frorneach of said orifices and operatively connected to said needle bar, said needle'bar having a lower horizontal said needle head is pressed upwardly by said spring assembly to insure that the needle tip is seated properly in its orifice despite any manufacturing variations in the dimensions of needle tips and orifices.

7. A spray gun for spraying adhesive on the fiaps of a carton comprising a housing adapted to be mounted in close proximity to a flap of a carton and having a cylinder in said cylinder and a piston rod extending therefrom, a spray head mounted on said housing and including a cap bolted to a base, a plurality of adhesive-spray orifices contained in said cap, a single adhesive chamber formed in said base and connected to each adhesive spray orifice atomizing-air orifices by air passages formed in said cap,

a needle bar connected to said piston rod and reciprocable thereby, and a longitudinally movable needle extending from each of said adhesive-spray orifices and operatively' connected to said needle bar, said spray head and needles being easily removable as a unit from maintenance or repair.

8. In a spray head for spraying adhesive on the flap of a carton, a spray head cap, a plurality of adhesive discharge nozzles positioned in said cap, an air discharge nozzle positioned around each of said adhesive nozzles, a spray head base bolted to said spray head cap, said air nozzles being connected to said base by air passages formed in said cap and base, a single adhesive chamber formed in said base and connected to each adhesive discharge nozzle by passages formed in said spray cap and base, a reciprocable needle bar, and a needle extending from each of said adhesive nozzles and detachably connected to said needle bar and reciprocable in unison theresaid housing for with, whereby to spray the flap of carton with uniform parallel stripes of adhesive as the ilap is moved along in proximity to the spray head.

9. A spray gun for spraying adhesive on the flaps of a carton comprising a housing adapted to be mounted in close proximity to a flap of a carton and having a cylinder formed therein, a piston having a piston head positioned in said cylinder and a piston rod extending therefrom, a

spray head bolted on said housing andincluding a cap bolted to a base, a plurality of adhesive-spray orifices contained in said cap, a single adhesive chamber formed in said base and connected to each adhesive spray orifice by passages formed in said spray head, an atomizing-air orifice positioned around each adhesive-spray orifice, an air passage formed in said base and connected to said atomizing-air orifices by air passages formed in said cap, an atomizing-air valve separate from said spray gun, an air gun so that the gun may be located at a point remote from the atcmizing-air valve, a needle bar connected to said piston rod and reciprocable thereby, and a longitudinally movableneedle extending from each of said adhesive spray orifices and operatively connected to said needle bar, said needle bar having a .lower horizontal member connected to said piston rod and having an upperhorizontal member with slots formed therein, each of said needles having a tip which seats in its orifice, a shaft conduit connecting said atomizing-air valve to said spray a which is received in oneof'said slots, and a head which is received in a space between the upper and lower hori- 8 t zontal members of said needle bar and is too large to pass through said slots, and a spring assembly supporting each needle head and mounted onsaid lower horizontal member of the needle bar, said spring assembly pressing upwardly against the needle head to insure thatthe needle tip is seated properly in its orifice despite any manufacturing variations in the dimensions of needle tips and orifices, said spray head and needles being easily removable as a unit from said housing for maintenance and repair by nnbolting said head from said housing and sliding the needles out of the slots in said needle bar, said spray head being easily disassembled for cleaning by unbolting the cap from the base. 1

References'Cited by the Examiner UNITED STATES PATENTS IOSEPH B. SPENCER, RICHARD D. NEVIUS,

' i Examiners. 

1. SPRAY GUN APPARATUS FOR SPRAYING ADHESIVE ON THE FLAPS OF A CARTON COMPRISING A SPRAY GUN HAVING A SPRAY HEAD WITH PLURALITY OF ADHESIVE-SPRAY ORIFICES AND ATOMIZING-AIR ORIFICES, AN AIR FILTER ADAPTED TO BE CONNECTED TO A SOURCE OF COMPRESSED AIR, A SPRAY GUN CONTROL LINE CONNECTED TO SAID AIR FILTER AND CONNECTING TOGETHER AN AIR PRESSURE REGULATOR, AN AIR LUBRICATOR, A GUN CONTROL VALVE, AND ACTUATING PISTON OF SAID SPRAY GUN, AN ATOMIZING AIR LINE CONNECTED TO SAID AIR FILTER AND CONNECTING TOGETHER AN AIR PRESSURE REGULATOR, AN ATOMIZING AIR VALVE, AND THE ATOMIZING AIR ORIFICES OF SAID SPRAY GUN, SAID ATOMIZING AIR VALVE BEING SEPARATE FROM SAID SPRAY GUN AND ADAPTED TO BE LOCATGED AT A POINT REMOTE FROM THE SPRAY GUN, A GLUE LINE OPERATIVELY CONNECTED TO SAID AIR FILTER AND CONNECTING TOGETHER AN AIR PRESSURE REGULATOR AND PRESSURIZED GLUE MEANS, AND A GLUE CONDUIT CONNECTING SAID GLUE MEANS TO THE ADHESIVE-SPRAY ORIFICES OF SAID SPRAY GUN, SAID SPRAY GUN HAVING A LONGITUDINALLY MOVABLE NEEDLE EXTENDING FROM EACH OF SAID ADHESIVE-SPRAY ORIFICES, AND MEANS FOR OPERATING SAID NEEDLES IN UNISON TO OPEN AND CLOSE SAID ADHESIVE-SPRAY ORIFICES.
 3. THE SPRAY GUN APPARATUS DEFINED IN CLAIM 1, WHEREIN IS PROVIDED CARTON SENSING SWITCH MEANS CONNECTED TO SAID GUN CONTROL AND ATOMIZING AIR VALVES FOR PREVENTING OPERATION OF SAID SPRAY GUNS UNLESS A CARTON IS POSITIONED SO AS TO BE SPRAYED THEREBY. 